The present invention relates to the vacuum tube arts. It finds particular application in connection with a device for linking a stator cord to the housing of an x-ray tube in CT scanners, and will be described with particular reference thereto. It should be appreciated, however, that the invention is also applicable to the formation of sealed couplings for other liquid-containing devices and x-ray tubes for other applications.
X-ray sources, such as those utilized in the field of medicine for the imaging of subjects, typically include a rotating anode contained within an evacuated envelope. The anode is connected with a rotor having a rotatable shaft. A stator circumferentially surrounds the rotatable shaft. During operation of the x-ray tube, a beam of electrons emitted by a cathode is accelerated towards the anode by a high voltage differential. The electrons strike a target area of the anode where they are converted to x-rays.
Only a small fraction of the energy of the electron beam is converted to x-rays, however. The majority of the energy is converted to heat, which heats the anode white hot. The x-ray tube envelope is commonly mounted within a housing filled with a cooling oil for carrying away some of the heat. Wires for the stator, filament heater, the voltage differential, and other electrical functions of the x-ray tube pass through the oil-filled housing and out through a port or ports in the housing wall. The wires from the stator (stator cord) typically continue for some distance to the controller for the x-ray tube, in some instances, as much as forty feet away.
To prevent leakage of the oil from the housing around the stator cord, the port in the housing is preferably sealed oil tight. In some applications, the wires are potted in epoxy or clamped by a plastic fitting. One such fitting has a flange with an O-ring on its underside and is held to the housing with screws. Another such fitting is formed from metal and has a peripheral flange and O-ring on the inside of the housing and a nut threadably received on the outside of the housing to hold the fitting in the wiring port with the O-ring firmly held against the adjacent housing.
Such fittings tend to be subject to some leakage. The oil in the housing is at relatively low pressure, and thus does not help to seal the O-ring against the housing. Additionally, the hard wiring created provides a wiring harness up to forty feet long, which is awkward and inconvenient. Further, if the x-ray tube is to be replaced, significant hand labor is employed to rewire the tube and reseal the ports through the housing.
The present invention provides a new and improved socket for connecting a wiring harness to an x-ray tube, and method of use, which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, an x-ray apparatus is provided. The x-ray apparatus includes an evacuated envelope and a stator, both within a housing. The stator generates a magnetic field for driving an anode within the envelope. A stator cord, exterior to the housing, electrically connects the stator with a source of power. A connection device, mounted to the housing, forms a releasable electrical coupling between the stator cord and the stator.
In accordance with another aspect of the present invention, a method of electrically connecting a stator cord, located exterior to a housing, with a stator, located within the housing, is provided. The method includes threading a threaded portion of a connecting device into a threaded aperture formed in the housing to provide a seal which resists leakage of liquid from the housing. The method further includes releasably connecting an electrical connector on the stator cord with a socket of the connecting device. The connecting device includes an electrical connection path which provides electrical connection between the socket and the interior of the housing.
In accordance with another aspect of the present invention, a device for connecting a stator cord, exterior to a housing of an x-ray tube, to a stator motor, positioned within the housing, is provided. The device includes a threaded portion for threadable connection with an aperture in a wall of the x-ray tube housing and a connection portion for releasably coupling with a connection member on the stator cord. An electrical conduction path has first and second ends. The first end extends into the connection portion for forming an electrical connection with the stator cord connection member. The second end extends into the threaded portion for forming an electrical connection with an electrical wire of the stator.
One advantage of the present invention is that leakage through the stator wiring port is reduced.
Another advantage of the present invention is that it enables a wiring harness to be readily connected and disconnected to an x-ray tube.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiment.